1. Field of the Invention
The present invention relates to a wireless communication system and, more particularly, to a method of reporting, by user equipment, system information in a wireless communication system and an apparatus for supporting the same.
2. Related Art
3rd generation partnership project (3GPP) long term evolution (LTE) which is improvement of a universal mobile telecommunications system (UMTS) is introduced as 3GPP release 8. The 3GPP LTE uses orthogonal frequency division multiple access (OFDMA) in a downlink and uses single carrier-frequency division multiple access (SC-FDMA) in an uplink. Multiple input multiple output (MIMO) having maximum four antennas are adopted. In recent years, 3GPP LTE-advanced (LTE-A) which is an evolution of the 3GPP LTE has been discussed.
A closed subscriber group (CSG) allows a limited access for only a specific subscriber to be introduced to provide a service having higher quality. A base station that can provide a CSG service may be home eNodeB (HNB) and a cell providing an authorized service to CSG subscribers may be a CSG cell. In the 3GPP, a basic requirement of the CSG is disclosed in 3GPP TS 22.220 V1.0.1 (2008-12) “Service requirements for Home NodeBs and Home eNodeBs (Release 9)”.
A feature of a CSG cell limitatively providing the service is illustrated even in handover to the CSG cell. Whether a user equipment (UE) is a CSG member of a corresponding cell may be problematic in performing the handover to the CSG cell. As a result, the handover to the CSG cell may be implemented by a first step in which the UE reports a cell measurement result and a second step in which the UE acquires system information from a target cell and reports the acquired system information to a service cell.
UE may acquire system information about a neighboring cell before being instructed by a serving cell to report the system information. When a system information reporting request for the corresponding neighboring cell is received, the UE can report ready-acquired system information. The ready-acquired system information has a particularity in that there is a temporal difference between a point of time at which the ready-acquired system information was acquired and a point of time at which the ready-acquired system information is reported. Accordingly, there is a need for a method of reporting system information, which supports that the validity of ready-acquired system information can be determined when reporting the ready-acquired system information.